Impact of addition of philosophical exemptions on childhood immunization rates.
 
																	
																		
																	
																		
																	
																	
																		
																	
																		
																	
																	
																			
																					
    Thompson JW, Tyson S, Card-Higginson P, Jacobs RF, Wheeler JG, Simpson P, Bost JE, Ryan KW, Salmon DA. Impact of addition of philosophical exemptions on childhood immunization rates. Am J Prev Med. 2007 Mar; 32(3):194-201.